Link to facebook message?

Hey guys, got a problem I need help with. I need to be able to (through a button in flash, or html at least) link to facebook, myspace, twitter, any of these social applications…but I need it to link to where it will have a message filled out and the user would just choose friends to send it to. Any help on this would be greatly appreciated, thanks so much. We’d like to be able to do this through a Flash exe on a kiosk but that sounds impossible, I think we’d need to do it through php on a website if I’m thinking correctly.